Cosmetic surgeon Patrick Treacy details his relationship with the King of Pop in Behind the Mask: The Extraordinary Story of the Irishman who became Michael Jackson's Doctor.

Speaking to Ryan Tubridy on RTE Radio 1 this week Dr Treacy described Jackson's skin condition, vitiligo, which affected the pigment in his skin.

"His skin was black and white and he depigmented his hands, his feet, and his face using sort of a bleaching agent that left him susceptible to skin cancers which is why he wore the mask in the sun all the time,” he said.

He added that Jackson should have told people about the condition.

“He should have been more honest with the world and put his hand up and said: ‘Look I have vitiligo and as a consequence of this I can’t go out in the sun,’” he said.

Dr Treacy established a relationship with Jackson, who sought out Treacy after he read about the doctor's charity work in Africa.

They were friends until the star's death in 2009 and Jackson even visited him and his children in Westmeath during their six month stay in Ireland.

However, the memoir contains just one chapter on Jackson. It is published by Liberties Press and available October 9, €17.99